Vacuum assisted aerated drilling

Abstract

A system and methods of using air compressors to create a jet vacuum to accelerate the drilling fluid circulation, which is located on the surface, or down the hole through passages along the well casings or drilling pipes. The jet vacuum is applied to help suck up the drilling fluids with cuttings. They are used in addition to the pumps and boosters to push and circulate the drilling mud or aerated-compound fluid. The invention accelerates the drilling fluid circulation and reduces the number of pumps and boosters.

What is claimed is: 
     
       1. A vacuum-assisted aerated drilling system, comprising: a casing, used for housing the borehole; a pump, used for pumping a drilling fluid into a drilling string and out of a drilling bit near a bottom of the borehole; at least one air compressor, used for creating a jet vacuum effect along the middle of drilling-fluid pathway to suck the drilling fluid pumped out of the drilling bit near the bottom of the borehole from a head of the borehole: and a circulation outlet pipe, wherein the circulation outlet pipe is placed horizontally or tilted upward at the head of the borehole, wherein the at least one air compressor includes a first air compressor, used for ejecting air into the circulation outlet pipe, so as to create a jet vacuum effect to suck the drilling fluid out of the drilling bit together with cuttings produced by the drilling bit into the circulation outlet pipe. 
     
     
       2. The vacuum-assisted aerated drilling system as claimed in  claim 1 , further comprising a separator, wherein the separator is used to receive the sucked drilling fluid together with the cuttings and separate the cuttings from the drilling fluid. 
     
     
       3. The vacuum-assisted aerated drilling system as claimed in  claim 2 , further comprising a curved, spiral or straight separation pipe, wherein the drilling fluid together with the cuttings are drawn into the separator through the curved, spiral or straight separation pipe. 
     
     
       4. The vacuum-assisted aerated drilling system as claimed in claim further comprising a plurality of separators, wherein the plurality of separators is used to receive the sucked drilling fluid together with the cuttings and separate the cuttings from the drilling fluid; and the plurality of separators is placed at different distances from the first air compressor, so as to collect the cuttings according to their weights and particle sizes. 
     
     
       5. A vacuum assisted aerated drilling system, comprising:
 a casing, used for housing the borehole; 
 a pump, used for pumping a drilling fluid into a drilling string and out of a drilling bit near a bottom of the borehole; and 
 at least one air compressor, used for creating a jet vacuum effect along the middle of drilling-fluid pathway and/or at earth surface to suck the drilling fluid pumped out of the drilling bit near the bottom of the borehole from a head of the borehole, 
 wherein the at least one air compressor includes a second air compressor, used for pushing a high pressured air into a passage that is extended firstly downward along the casing and then reverted in 180 degrees upward, so as to create a jet vacuum effect to suck the drilling fluid out of the drilling bit together with cuttings produced by the drilling bit upward. 
 
     
     
       6. The vacuum-assisted aerated drilling system as claimed in  claim 5 , further comprising a separator, wherein the separator is used to receive the sucked drilling fluid together with the cuttings and separate the cuttings from the drilling fluid. 
     
     
       7. The vacuum-assisted aerated drilling system as claimed in  claim 6 , further comprising a curved, spiral, or straight separation pipe, wherein the drilling fluid together with the cuttings are drawn into the separator through the curved or straight connecting pipe. 
     
     
       8. The vacuum-assisted aerated drilling system as claimed in  claim 5 , further comprising a plurality of separators, wherein the plurality of separators is used to receive the sucked drilling fluid together with the cuttings and separate the cuttings from the drilling fluid; and the plurality of separators is placed at different distances from the second air compressor, so as to collect the cuttings according to their weights and particle sizes.